The disclosed embodiments of the present invention relate to flashlight control, and more particularly, to a control method of an electronic device having a dynamically controlled flashlight for image capturing and a related electronic device with an image capture function.
A flashlight of a conventional camera turns on automatically to provide extra light whenever the light level is low for a good exposure or when a main subject is backlit, wherein a flashlight output is determined according to a brightness value (BV), an aperture value, an exposure time (a shutter speed) and/or an ISO speed of the camera. In addition, the flashlight turns on according to a scene (e.g. a landscape scene or a portrait scene) analyzed by the camera.
However, the flashlight has a limited effective flash output distance. For example, an effective flash output distance of a conventional camera phone is about two to three meters. Hence, even though a flashlight of the camera phone turns on according to a light level in the environment or an analyzed scene, the flashlight cannot provide sufficient light for a subject when the subject is far away from the camera phone. Specifically, an exposure time is relatively short because an auto exposure (AE) algorithm assumes that the flashlight can brighten the subject, thus resulting in a relatively dark subject. Further, battery power of the camera phone consumes while the flashlight has no help to brighten the subject, resulting in wasting the battery power.
Thus, there is a need for a novel control mechanism to dynamically control a flashlight of an image capturing apparatus.